The worldwide epidemic of overweight and obesity affects about 1.7 billion people around the world. Since 1991, many international medical societies have established as recommendation for bariatric surgery the unsuccessful clinical treatment in patients with IMC > 40Kg/m2 or IMC > 35Kg/m2 in the cases with serious co-morbidities related to the possible reversion of them with the lose of weight due to the surgery. In front of the new anatomical condition from the gastrointestinal tract the patients present changes in food preferences and in the food intake, which include modifications in food choices, perception of hungry and satiety and in the tolerance to determinate food. These changes in food intake of the patients are observed mostly in the first year after the surgery an adaptive phase to a new condition.